Photographic products, processes, and compositions



United States Patent PHOTOGRAPHIC PRODUCTS, PROCESSES, AND COMPOSITIONSRichard S. Corley, Wellesley Hills, Mass., assignor t0 PolaroidCorporation, Cambridge, Mass., a corporation of Delaware No Drawing.Filed Jan. 31, 1955, Ser. No. 485,342

19 Claims. (Cl. 9629) This invention relates to photography and moreparticularly to products, compositions and processes for the developmentof photosensitive silver halide elements.

It is one object of the present invention to provide novel processes andcompositions for the development of silver halide emulsions, in whichcolored developing agents are used to develop a latent photographicimage.

Another object is to provide novel processes and compositions for thedevelopment of silver halide emulsions, in which the novel developingagent is capable of developing a photographic latent image and impartinga reversed or positive colored image of said latent image to asuperposed image-receiving element.

A further object is to provide novel products, processes andcompositions suitable for use in preparing monomchromatic andmultichromatic photographic images.

A still further object is to provide a method of changing the colorproperties of colored developing agents whereby colored developingagents of desired colors may be obtained from colored developing agentsof similar chemical composition.

Other objects of this invention will in part be and will in part appearhereinafter.

The invention accordingly comprises the processes involving the severalsteps and the relation and order of one or more of such steps withrespect to each of the others, and the products and compositionspossessing the features, properties and the relation of elements whichare exemplified in the following detailed disclosure, and the scope ofthe application of which will be indicated in the claims.

The objects of this invention may be accomplished by the use of certaincompounds hereinafter described, which possess the ability to functionboth as a dye and as a photographic developing agent. These compoundsmay therefore be referred to as dye developers.

obvious The photographic processes and compositions disclosed herein areparticularly useful in the treatment of a latent image present in aphotosensitive element, such as an exposed silver halide emulsion,whereby a positive dye image thereof may be imparted to another element,herein referred to as an image-carrying or image-receiving element, aswill be further described herein.

U.S. Letters Patent Nos. 2,559,643 and 2,647,049 to Edwin H. Landdisclose examples of such diffusion trans fer reversal processes whereina photographic material, such as a photosensitive element comprising anexposed silver halide emulsion layer containing a latent image, isprocessed to impart to an image-carrying element a reversed or positivedye image of said latent image by permeating into said emulsion layer asuitable liquid processing composition and bringing said photosensitiveelement into superposed relationship with an appropriate image-receivingelement.

In carrying out the process of this invention, a photosensitive elementcontaining a silver halide emulsion is exposed and a liquid processingcomposition applied 2 thereto, as by immersing, coating, spraying,flowing, etc., in the dark, and the photosensitive element superposed,prior to, during or after wetting, on an image-receiving element. In apreferred embodiment, the photosensitive element contains a layer of thedye developer, and the liquid processing composition is applied to thephotosensitive element in a uniform layer as this element is broughtinto superposed relationship with an imagereceiving element. The liquidprocessing composition permeates the emulsion and provides a solution ofthe dye developer substantially uniformly distributed therein. As thesolubilized dye developer develops the latent negative image to silver,its oxidation product is immobilized or precipitated in situ with saidsilver. This immobilization is apparently due, at least in part, to achange in the solubility characteristics of the dye developer uponoxidation, and especially as regards its solubility in alkalinesolutions. It may also be due, in part, to a tanning effect on theemulsion by the oxidized dye developer. The unoxidized dye developerretains its solubility in the liquid processing composition, therebyproviding an imagewise distribution of unoxidized dye developer, atleast part of which is transferred, by imbibition, to a superposedimage-receiving element, said transfer substantially excluding silver oroxidized dye developer. The latter element receives a depthwisediffusion, from the emulsion, of unoxidized dye developer withoutappreciably disturbing its irnagewise distribution, thereby giving areversed or positive, colored image of the developed negative image.The. image-receiving element may contain agents adapted to mordant orotherwise fix the diflfused, unoxidized dye developer. If the color ofthe diffused dye developer is aifected by changes in the pH of theimage-receiving element, this pH may be adjusted in accordance withknown techniques to provide a pH according the desired color. Imbibitionperiods of approximiately one minute have been found to give goodresults, but this contact period may be adjusted where necessary tocompensate for variations in temperature or other conditions. Thedesired positive image is revealed by stripping the image-receivingelement from the photosensitive element at the end of the imbibitionperiod.

The novel dye developers disclosed herein may be utilized in the liquidprocessing composition, in the imagereceiving element, or in thephotosensitive element, as for example, in, on or behind the silverhalide emulsion layer. When employed in either element, the dyedeveloper becomes solubilized by the liquid processing composition as itpermeates the element. In a preferred embodiment, a coating or layer ofthe dye developer is placed behind the silver halide emulsion layer,i.e., on the side of the emulsion layer adapted to be located mostdistant from the photographed subject when the photosensitive element isexposed. This coating of the dye developer is preferably also located onthe side of the emulsion layer adapted to be most distant from theimagereceiving element when in superposed relationship therewith.Placing the dye developer behind the emulsion layer, as in the preferredembodiment, has the advantage of providing increased contrast in thepositive image, and also minimizes any light-filtering action by thenovel colored dye developer. In this preferred embodiment, the dyedeveloper coating may be applied by using coating solutions containingabout 0.5 to 8%, by weight, of the dye. developer." Similarconcentrations may be used if the dye developer is utilized as acomponent of the liquid amount of a conventional developing agent. Ifthe liq 1 uid processing composition is to be applied to the emulsion bybeing spread thereon, preferably in a relatively thin, uniform layer, itmay also include a viscosity-increasingcompound constitutingfilm-forming material of the type which, when spread over awater-absorbent base, will form a relatively firm and relatively stablefilm. A preferred film-forming material is a high molecular weightpolymer such as a polymeric, water-soluble ether which is inert to analkaline solution, as, for example, a hydroxyethyl celluloseor sodiumcarboxymethyl cellulose, Other film-forming materials or thickeningagents may be employed whose ability to increase viscosity issubstantially unaffected when left in solution for a long period oftime.

It has been discovered that dye developers having amino-nitrogenatoms aspart of their chromophoric system may. have their color propertiesaltered by acylation of such amino-nitrogen atoms. This has been foundto be particularly applicable to dye developers having aminonitrogenatoms attached directly to the anthraquinone nucleus.

The novel dye developers which may be used to accomplish the objects ofthis invention may be represented by the formulae:

A represents an anthraquinone nucleus;

X represents an organic radical containing hydroxyl substituentsimparting a silver halide developing function thereto;

R represents an acyl group, which may be aliphatic, e,.g., acetyl, oraromatic, e.g., benzoyl;

Z is a bivalent organic radical containing at least one methylene (CHgroup;

m is a positive integer less than 5; and

Bach Y may be hydrogen, amino, alkyl, aryl, nitro, halogen, alkylamino,arylamino, aryloxy, alkoxy, hydroxyl, sulfonamido, carboxamido, carboxy,sulfo,

wherein Q may be hydrogen or alkyl.

The expression bivalent organic radical refers to organic radicalshaving the two free valences attached to different atoms. As examples ofsuitable bivalent organic radicals comprehended by the radical Z,mention may be made of alkylene radicals such as --CH as well asbivalent radicals such as It is also intended that Z may be saturated,unsaturated, such as CH r-CH=CH--CH or substituted, such aschloroalkylene or hydroxyalkylene. Experience has indicated that where Zis an alkylene group, best results are obtained by the use of a loweralkylene group, e.g.,

an alkylene group containing less than about six carbons,

and preferably an ethylene (CH CH group. Alkylene groups containing morecarbons may be used, however, provided that the resulting dye developeris capable of being dissolved in the liquid processing composition de tscribed herein, and its oxidization product rendered immo-.

bile in the developed emulsion layer.

X has been defined as an organic group containing hydroxyl substituentswhich impart to it a silver halide developing function. Although, in apreferred embodiment, X contains a benzene nucleus substituted in thepara positions, with respect to each other, by hydroxyl groups, this isintended tobe illustrative only. Thus, for example, a silver halidedeveloping function may be imparted tov an aryl nucleus, by hydroxylgroupswhich are substituted in the ortho or para positions, with respectto each other, of a benzene nucleus, or in the 1,2 or 1,4 positions of anaphthalene nucleus. It is tobe noted also that X may containsubstituents. other than those hydroxyl groups which supply the silverhalide developing function so long as such substituents do not destroythe silver halide developing ability; such substituents include alkyl,hydroxyl, amino, halogen, etc. Reference is made to The Theory of thePhotographic Process, C. E. Mees (1st Ed, 1942), The Macmillan (30., NewYork, N. Y.', p. 342 et seq., for a discussion of the chemicalconstitution of silver halide developing groups.

Where the developing function possessed by X is supplied by hydroxylgroups, it may be desirable to protect these groups as by acylation, toavoid side reactions or oxidation. The protective groups are removed, asby hydrolysis, prior to photographic use.

The novel dye developers of thisinvention are preferably;

prepared by heating the corresponding amino compounds with theappropriate acid halide or acid anhydride. Other known methods ofacylation may also be used, such as use of an ester or amide ofthe acid.By suitable control of reaction conditions and ratios of the acylatingagent and. the amino compound, acylation may be brought about at one ormore amino-nitrogen atoms. It is also within the scope of this inventionto introduce different acyl groups into a compound having more than oneamino-nitrogen in the chromophoric system.

Acylation of amino-nitrogen atomswhich are of the chromophoric systemhas the effect of shifting the visible absorption band of the compoundtoward higher frequencies (shorter wave lengths). Thus, acylatingoneamino-nitrogen of the cyanl,4-bis.-[beta-(2',5'-dihydroxyphenyD-ethylamino]-anthraquinone changesits color to a magenta and acylating both the amino-nitrogen atomschanges its color to an orange-yellow.

As examples of suitable amino-anthaquinone com-.

pounds whichrnay be acylated in accordance with this invention, mentionmay be made of 1,4-bis-(2',5'-dihydroxyanilino)-anthraquinone andsimilar compounds as disclosed and, claimed in the copending applicationof Elkan R. Blout and Myron S. Simon, Serial 449,514, filed August 12,1954, now abandoned in favor of a continuation-in-part applicationSerial No. 849,727, filed 0c Example 1 1,4-bis-[beta-(3:,4-dihydroxyphenyl) -ethylamino] -anthraquinone. and benzoyl chloridein 1:1 molar proportions are refluxed in approximately 10, volumes: of

acetone until the color change from cyan to magenta is complete. Theacetone solution is then concentrated and the residuetwicerecrystallized from acetone-chlorm form. totobtain a. 32% yield 1 ofN-monobenzoyl-lfl-bis [beta (3',4f dihydroxyphenyl) ethylamin'o]anthraqumone of the formula: v.

( N-CHaOH on d NH-CHiCH on ("nlm'llafnfl 68. 77 4. 67 4. 33 Found 68. 64. 6 4. 1

An example of a photographic use of the dye developers of thisinvention, and set forth as an illustration only, is:

Example 2 A photosensitive element is prepared by coating a subcoatedcellulose acetate film base with a 4% aqueous gelatin solution. Afterthis coating has dried, a coating is applied of a solution comprising 2g. of the dye developer of Formula III as prepared in Example 1, above,in:

Cellulose acetate hydrogen phthalate g 4 Acetone cc 80 Methanol cc 20 Asilver-iodobromide emulsion is applied after the above coating hasdried. An image-receiving element is prepared by applying a polyvinylbutyral coating to a cellulose acetate coated baryta paper, followed bya coating of a solution comprising:

Nylon Type F8 (trade name of E. I. do Pant de Nemours & Co., Wilmington,Delaware, for N- ;methoxymethyl polyhexamethylene adipamide) g 4 Ethanolcc 85 Furfurylalcohol cc 15 The photosensitive element is exposed andbrought into superposed relationship with the image-receiving element asa liquid processing composition is spread between said elements. Thisliquid processingcomposition comprises:

Sodium hydroxide -L g 1.5 Water cc 100 Metol g 0.1 Sodium carboxymethylcellulose (very high viscosity) g 4.5

After imbibition period of approximately one minute,

the image-receiving element is separated and contains a magenta positiveimage of the photographed subject.

A further example of a photographic use of a dye developer within thescope of this invention is:

6 Example 3 A photosensitive element is prepared as described in Example2, above, except that the dye developer coating solution comprises:

N monobenzoyl 1,4 bis [beta (2',5'dihydroxyphenyl)-ethylamino]-anthraquinone (prepared in a manner similarto that described in Example 1) g 3 Cellulose acetate hydrogen phthalateg 4 Acetone cc-.. Methanol cc 20 An image-receiving element is preparedby applying a polyvinyl butyral coating to a cellulose acetate coatedbaryta paper, followed by a coating of a solution comprising:

Nylon Type F8 g 4 Ethyl alcohol ...Q cc Furfuryl alcohol cc 15 Thephotosensitive element is exposed and brought into superposedrelationship with the image-receiving element as a liquid processingcomposition is spread. between said elements. This liquid processingcomposition comprises:

Water cc. Sodium carboxymethyl cellulose (very high viscosity) -4 g 4.5Sodium hydroxide g 2.0 Metol g 0.2 Potassium bromide g 0.2 Sodiumcarbonate g 2.0

After an imbibition period of approximately one minute, theimage-receiving element is separated and contains a magenta, positiveimage of the photographed subject.

It will be noted that the liquid processing composition may, and in theaboveexamples does, contain a minor amount of a conventional developer,such as Metol. The amount of this conventional developer used isinsuflicient to develop the latent image by itself, and merely serves I1-2% of the dye developer, 1% sodium hydroxide,

2% sodium sulfite and 0.05% potassium bromide. After development iscompleted, any unreacted dye developer is washed out of thephotosensitive element, preferably with an alkaline washing medium orother medium in which the unreacted dye developer is soluble. Theexpression toned is used to designate photographic images wherein thesilver is retained with the precipitated dye, whereas monochromatic isintended to designate dye images free of silver.

It should be noted that the dye developers of this invention areself-sufficient to provide the desired color image and do not dependupon coupling reactions to produce the desired color. They thus providea complete departure from conventional photographic color processes inwhich the color is produced by a coupling reaction involving theoxidized developing agent.

It will be apparent that, by appropriate selection of theimage-receiving element from among suitable known opaque and transparentmaterials, it is possible to obtain either a colored positive reflectionprint or a colored positive transparency. Likewise, the inventiveconcepts herein set forth are adaptable for multicolor work by the useof special photographic materials, for example film materials of thetype containing two or more photosensitized elements associated with anappropriate num- '2" her of image-receiving elements and adapted to betreated with one or more liquid "processing compositions, appropriatedyedevelopers suitable to impart: the desired subtractive colors beingincorporated in thcphotosensiand claimed in the copending application ofHoward G.

Rogers, Serial No. 415,073, filed March 9, 1954, now abandoned in favorof a continuation-in-part application Serial No. 748,421, filed July 14,1958, and also those set forth in the copending application of Edwin H.Land, Serial No. 448,411, filed August 9, 1954, now US. Patent No.2,968,554, issued January 17, 19.61.

In the preceding portions of the specification: the. ex:

pression color has been frequently used. This expression-is intended toinclude the use of a plurality of colors to obtain black, as Well asthe. use ofa single black dye developer.

Since certain changes may be made in the above products, compositionsand processes without departing from the scope of the invention hereininvolved, it is intended that all matter contained in the abovedescription shall be interpreted as illustrative and not ina limitingsense.

What is claimed is 1. A photographic developer composition comprising anaqueous solvent, an alkaline material soluble therein, and a compoundselected from the group consisting of:

B (8m) )m and t Y a- )A (N-X) m wherein A is an anthraquinone nucleus, Xis an organic radical selected from the group consisting of orthoandpara-dihydroxyphenyl and orthoand para-dihydroxynaphthyl radicals, R isan acyl group of an organic carboxylic acid, Z is a bivalent hydrocarbonradical containing at least one methylene group, m is a positive integerless than 5, each Y is selected from the group consisting of hydrogen,amino, alkyl, aryl, nitro, halogen, alkylamino, arylamino, aryloxy,alkoxy, hydroxyl, sulfonamido, carboxamido, carboxy, sulfo,

t t N-ZX and N-X radicals, and Q is selected from the group consistingof hydrogen and alkyl radicals.

2. A photographic developer composition as defined in claim 1 whereinsaid X is a para-dihydroxyphenol radical.

3. A photographic developer compositioncomprising an aqueous solvent, analkaline material soluble therein, and N monobenzoyl 1,4 bis [beta(3',4' dihydroxyphenyl) -ethylamino] -anthraquinone.

4. A photographic developer composition, comprising an aqueous solvent,an alkaline material soluble therein, and N monobenzoyl 1,4 bis [beta(2,,5' dihydroxyphenyl -ethylamino] -anthraquinone.

5. A process of developing a latent imagev contained in an exposedphotosensitive silver halide emulsion which comprises treating saidemulsion with an aqueous alkaline solution of a compound selected fromthe group consisting of compounds represented by the formulae:

(s-m (N )m and wherein A is an anthraquinone nucleus, X is'anaryl'radical selected from the group consisting of'orthoandpara-dihydroxyphenyl and orthoand para-dihydroxynaphthyl radicals, R isan acyl group of an organic carboxylic acid, Z is a bivalent hydrocarbonradical containing at least one methylene group, m is a positive integerless than 5, each Y is selected from the group consisting of hydrogen,amino, alkyl, aryl, nitro, halogen, alkylamino, arylamino, aryloxy,alkoxy, hydroxyl, sulfonamide, carboxamido, carboxy, sulfo,

radicals, and Q is selected from the group consisting of hydrogen andalkyl radicals.

6. A process of developing a. latent image contained in an exposedphotosensitive silver halide emulsion which comprises treating saidemulsion with an aqueous alkaline solution of N monobenzoyl 1,4 bis[beta (3',4- dihydroxy)-ethylamino]-anthraquinone for a time suilicientto develop the latent image to silver. 7

7. A process of developing a latent image contained in an exposedphotosensitive silver halide emulsion which comprises treating saidemulsion with an aqueous alkaline solution of N monobenzoyl 1,4 bis[beta (2',5- dihydroxyphenyl)-ethylamino]-anthraquinone.

8. In a process of forming a photographic image in color, the stepswhich comprise developing a latent image contained in an exposedsilverhalide emulsion with an aqueous alkaline solution containing a dyedeveloper selected from the group consisting of:

wherein A is an anthraquinone nucleus, X is an aryl radical selectedfrom the group consisting of orthoand para-dihydnoxyphenyl and orthoandpara-dihydroxynaphthyl radicals, R is an acyl group of an organiccarboxylic acid, Z is a bivalent hydrocarbon radical containing at leastone methylene group, m is a positive integer less than 5, each Y isselected from the group consisting of hydrogen, amino, alkyl, aryl,nitro, halogen, alkylamino, arylamino, aryloxy, alkoxy, hydroxyl,sulfonamido, carboxamido, carboxy,sulfo,

radicals, and Q is selected from the group consisting of hydrogen andalkyl radicals, to thereby provide in said emulsion layer a'predetermined distribution of unoxidized dye developer, and transferringat least part of said distribution of unoxidized dye developer byimbibition from said emulsion layer to an image-receiving element insuperposed relationship with said' emulsion to impart to saidimage-receiving element a reversed, positive dye image of the developedimage.

9. A process as defined in claim 8'wherein saidaqueous alkaline solutioncontains an accelerating developer.

10. The process as defined in claim 8, wherein said X is apara-dihydroxyphenyl radical.

11. The process as defined in claim 8, wherein said dye developer isN-monobenzoyl-1,4-bis-[beta-(3',4-dihydroxyphenyl) -ethyl amino]-anthraquinone.

12. The process as defined in claim 8, whercinsaid dye developer isN-monobenzoyl-1,4-bis-[beta-(2',5'-dihydroxyphenyl) -ethylarnino]-anthraquinone.

13. The process as defined in claim 8, wherein said dye developer is.disposed, prior to exposure, in the-photosensitive element comprisingsaid exposed silver halide emulsion, and the solution containing saiddye developer is formed bypermeatingsaid photosensitive element with anaqueous alkaline liquid capable of solubilizing said dye developer.

14. The process as defined in claim 13, wherein said liquid isintroduced by being spread in a substantially uniform layer between saidphotosensitive element and said image-receiving element as said elementsare brought into superposed relationship.

15. The process as defined in claim 14, wherein said liquid contains athickener for increasing viscosity and for facilitating the spreadingthereof between said photosensitive element and said image-receivingelement.

16. The process as defined in claim 8, wherein said dye developer isdissolved in an aqueous alkaline solution prior to application thereofto said exposed emulsion.

17. In a photographic product comprising a plurality of layers includinga layer containing a silver halide emulsion and having a silver halidedeveloper disposed in at least one layer, the feature of having saidsilver halide developer be a compound selected from the group consistingof:

R Y s-m -A(I TZX)m and i Y s-m)A-(N-X)m wherein A is an anthraquinonenucleus, X is an aryl radical selected from the group consisting oforthoand radicals, and Q is selected from the group consisting ofhydrogen and alkyl radicals.

18. A photographic product comprising a silver halide emulsion and Nmonobenzoyl 1,4 bis [beta (3,4-'- dihydroxyphenyl) -ethyl amino]-anthraquinone.

!19. A photographic product comprising a silver halide emulsion and Nmonobenzoyl 1,4 bis [beta (2',5'- dihydroxyphenyl) -ethylamino]-anthraquinone.

References Cited in the file of this patent UNITED STATES PATENTS742,405 Eichengrun et a1. Oct. 27, 1903 1,660,090 Perkin et al Feb. 21,1928 2,123,375 Mieg et al July 12, 1938 2,192,891 Borst Mar. 12, 19402,559,643 Land July 10, 1951 UNITED STATES PATENT OFFICE CERTIFICATIONOF CORRECTION Patent No. 2,983,605 May 9, 1961 Richard S. Corley It ishereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 1, line 30, for "monomchromatic" read monochromatic column 2,line 37, for "miately" read mately column 4, lines 46 and 55, for"anthaquinone" each occurrence, read anthraquinone same column, line 51,after "S'erial" insert No. column 5, line 54, for

"Pant" read Pont column 7, line 55, for "para-dihydroxy V phenol" readpara-dihydroxyphenyl column 8, line 20,

for "dihydroxy" read dihydroxyphenyl Signed and sealed this 24th day ofOctober 1961,

(SEAL) Attest;

ERNEST wt, SWIDER DAVID L; L Attesting Officer Commissioner of Patents

8. IN A PROCESS OF FORMING A PHOTOGRAPHIC IMAGE IN COLOR, THE STEPSWHICH COMPRISE DEVELOPING A LATENT IMAGE CONTAINED IN AN EXPOSED SILVERHALIDE EMULSION WITH AN AQUEOUS ALKALINE SOLUTION CONTAINING A DYEDEVELOPER SELECTED FROM THE GROUP CONSISTING OF: